Burs-IA Utils

HMAC-SHA1

hmac-sha1

Read-onlyIdempotent

Calcula el HMAC (RFC 2104) con SHA1. Cuándo: hay que firmar un mensaje, o comprobar una firma, con un secreto compartido que viene en la llamada. No para: calcular el HMAC (hmac-sha256). Efectos secundarios: ninguno (solo lectura, sin red, sin estado guardado). Determinista: la misma entrada da la misma salida. Límites: entrada JSON de hasta 64 KB, 1 s por llamada, resultado de hasta 1 MB.

EN: Computes the HMAC (RFC 2104) using SHA1 over text, hex or base64 data with a text, hex or base64 key. Uses a legacy hash; HMAC remains usable for interop, SHA-256 is the modern default. When: a message has to be signed, or a signature checked, with a shared secret supplied in the call. Not for: computing the HMAC (hmac-sha256). Side effects: none (read-only, no network access, no stored state). Deterministic: the same input gives the same output. Limits: JSON input up to 64 KB, 1 s per call, result up to 1 MB.

Input Schema

Name	Required	Description	Default
`key`	Yes	Secret key (string; required; up to 4096 chars).
`data`	Yes	Input data (string; required).
`key_encoding`	No	Encoding of `key` (optional; one of: utf8, hex, base64; default "utf8").	utf8
`input_encoding`	No	How `data` is encoded (optional; one of: utf8, hex, base64; default "utf8").	utf8
`output_encoding`	No	Output encoding of the digest (optional; one of: hex, base64, base64url; default "hex").	hex

Output Schema

Name	Required	Description	Default
`mac`	No
`encoding`	No
`algorithm`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedNov 2, 2026
- addedInput schema / properties / data / examples
```
Added value: +[
+  "The quick brown fox jumps over the lazy dog"
+]
```
- addedInput schema / properties / key / examples
```
Added value: +[
+  "key"
+]
```
First observedNov 1, 2026

TDQS

A4.6/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Adds substantial context beyond annotations: no side effects, no network, no stored state, deterministic output, and explicit runtime/input/result limits. It also discloses the legacy-hash caveat, which is valuable behavioral guidance for an agent choosing the tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The content is dense and well organized, with purpose, usage, exclusions, side effects, determinism, and limits presented in order. However, the full Spanish and English duplication makes it longer than necessary for a single-locale agent.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Complete for this tool: it covers when to use it, when not to, safety/state behavior, determinism, limits, and the legacy-hash caveat. Since an output schema exists, the description need not explain return values.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the schema already documents all five parameters, their defaults, and enums. The description restates text/hex/base64 handling for data and key but adds little beyond the schema, and its 64 KB JSON input limit sits oddly against the schema's 1 MB data maxLength.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific operation and algorithm: computes HMAC (RFC 2104) using SHA1 over data with a key. It explicitly contrasts with hmac-sha256 and notes SHA-1's legacy status, so an agent can distinguish it from sibling hash/HMAC tools.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives clear when-to-use guidance: signing a message or checking a signature with a shared secret supplied in the call. It explicitly names the alternative for modern use, hmac-sha256, and frames SHA-1 as interop-only.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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