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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description adds valuable context by specifying the returned content (contact/profile fields, tags, publication links, statistics) and by noting 'where WhatDoTheyKnow exposes them,' which aligns with the open-world hint. It does not discuss errors or rate limits, but this is not critical for a read-only getter.

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 three sentences, each serving a distinct purpose: statement of behavior, summary of returned data, and usage note. There is no repetition or filler, and the structure front-loads the core purpose.

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 one-parameter, read-only tool with an output schema and strong annotations, the description is complete. It covers the return contents, the important slug format nuance, and provides a fallback lookup path. The output schema already handles return-value details, so no further exposition is necessary.

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?

The input schema provides no description for authority_slug (0% coverage), but the description compensates with a clear format rule: underscores not hyphens, a concrete example ('home_office' not 'home-office'), and a pointer to search_authorities for finding valid slugs. This adds meaningful guidance beyond the raw schema.

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 begins with a clear, specific verb+resource combination: 'Return full public JSON for a WhatDoTheyKnow public authority.' It distinguishes this from siblings by stating it covers authority data, and the closing reference to search_authorities further clarifies the boundary.

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 explicitly directs users to 'Use search_authorities to find the correct slug,' providing an alternative for a specific prerequisite. However, it does not fully contrast when to choose get_authority_detail over other sibling detail tools like get_request_detail, though the resource difference is implicit.

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