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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly declares the tool is read-only and SSRF-guarded, which is excellent transparency for a security scanning tool. The only minor gap is not specifying output size or timeout behavior, but the terms 'Read-only' and 'SSRF-guarded' are sufficient for safe invocation.

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 extremely concise, single sentence with a dash and two additional attributes. Every element adds meaning: action (run scan), target (https URL), subject (TLS/security-header posture), result (Obelisk Rating), and safety flags (read-only, SSRF-guarded). Zero waste.

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?

The tool is simple with one param, good schema coverage, and no output schema. The description covers purpose, scope, and safety but lacks return format details (e.g., whether rating is a string/number/range). However, given with sibling tools like explain_rating, the agent can infer the rating is a defined type. Sufficient for a straightforward scan tool.

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%, meaning the schema already documents the one parameter (url). The description adds the constraint 'https URL' and provides a concrete example, which is useful but not extensive. Baseline 3 is appropriate since the schema already does the primary documentation work.

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 clearly states the tool performs an Obelisk public trust scan on an https URL, assessing TLS and security-header posture and scoring it as an Obelisk Rating. This specific verb+resource combination ('run Obelisk's public trust scan') effectively distinguishes it from sibling tools which cover explaining ratings, gate status, organization ratings, etc.

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?

The description indicates when to use the tool (on https URLs for trust scanning) but does not explicitly state when not to use it. While alternatives are implied through sibling tools like explain_rating, no direct exclusions or comparative guidance is provided.

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