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

With no annotations, the description alone must disclose behavioral traits such as side effects, data access, or safety. It mentions nothing about whether the tool is read-only, what it modifies, or what it returns. The only behavioral hints appear inside parameter descriptions ('discarded after...'), but tool-level behavior remains completely opaque.

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

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

The description is very short, but the brevity is under-specification rather than genuine conciseness. It is a fragment lacking a verb or any explanatory structure, so the short length is not an asset.

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

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

For a tool with nine heterogeneous parameters, no output schema, and no annotations, one cryptic phrase is wholly inadequate. An agent cannot determine which parameter to supply, what the tool expects, what it will return, or even its basic purpose, making the description dangerously incomplete.

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

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

Schema description coverage is 100%, so the baseline is 3. The tool description adds no parameter-level meaning and does not explain how any of the nine parameters relate to 'JDN modulo 7 weekday band'. It neither clarifies nor obfuscates the schema, but it certainly doesn't compensate for the semantic disconnect.

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

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

The description 'JDN modulo 7 weekday band' is a noun phrase, not a statement of operation. It never says what the tool actually does (compute, validate, return?), and it fails to connect to any of the nine parameters, leaving the agent unable to infer its function or distinguish it from siblings.

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

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

No usage guidance is provided. The description gives no indication of when to choose jdn-mod over the many siblings such as timezone, validate-json, fetch-status, or normalize-url, and it offers no conditions, exclusions, or alternative selection cues.

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