nonprofit_fetch_charity_uk

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

No annotations provided, so the description carries full burden. It declares read-only, no side effects, idempotent, UK-only, 24-hour cache, and verified source. It does not detail error handling or rate limits, but covers key behavioral traits well.

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 well-structured with a clear lead sentence, but the feedback instructions at the end add length. Could be slightly more concise, but it is not verbose.

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?

With one simple parameter and an output schema present, the description covers input, output fields, caching, source, and usage boundaries. It lacks error examples or response format details but is otherwise complete for this tool's complexity.

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 0%, but the description explains the parameter format ('7 digits, e.g. 1234567') and that it can be a number or name. This adds meaning beyond the schema, though it could mention case sensitivity or partial matching.

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 uses a specific verb ('Fetch') and resource ('UK registered charity details'), clearly distinguishing it from sibling tools for US nonprofits. It immediately states the purpose and scope.

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?

Explicitly states 'Use this for UK charities' and names two alternative tools for US nonprofits. Also provides a fallback reporting mechanism, giving clear when-to-use and when-not-to-use guidance.

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