fetch

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the 180-line truncation cap and the next_line continuation mechanism, which tells the agent the result may be partial.

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?

Two sentences with no filler. The core capability and its scope limit are front-loaded, and the follow-up action comes second where it belongs.

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 read-only tool with full annotation coverage and no output schema, the description supplies the essentials: input forms, result size limit, and the continuation path. Minor gaps (e.g. behavior when a document is shorter than 180 lines) are not material to correct invocation.

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 coverage is 0% and the single parameter is only titled 'Id', so the schema alone is ambiguous. The description resolves the ambiguity by stating the id accepts either a search result ID or a URL, which is the key thing an agent needs to supply a valid argument.

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?

Names a specific verb (read/fetch) and resource (indexed document), plus the concrete scope (first 180 source lines) and accepted inputs (search result ID or URL). It also implicitly separates itself from the sibling read_wiki_page, which it frames as the continuation path rather than the initial fetcher.

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?

Gives clear conditional routing: when the response carries a next_line, continue with read_wiki_page. That names an alternative tool and the condition selecting it. It stops short of stating when to prefer fetch over search/search_wiki for obtaining the initial ID, so no explicit exclusions are provided.

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