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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered and the description need not restate it. What the description does add is genuinely useful: the search corpus is limited to title and body text, not comments, diffs, or code. It says nothing about result ordering, pagination, or truncation behavior tied to the undocumented 'limit' parameter.

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?

A single sentence that front-loads the verb and resource and packs the search corpus and scoping into the same clause. Nothing is redundant and nothing could be trimmed without losing information.

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 search tool with no output schema, the description covers the essentials: what is searched, in what field, and within what scope. The remaining omissions (result ordering, limit semantics) are minor and partly carried by the 'state' enum documented in the schema.

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 only 20% (just 'state'), so the description carries real weight here, and it does clarify that 'query' matches against title/body and that owner/repo scope the search. However, 'limit' is left completely undefined in both the schema and the description, leaving a meaningful gap for a 5-parameter tool.

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 gives a specific verb and resource ('Search pull requests') plus the matching scope ('by title/body keyword on a repo'), which separates it from mutation siblings like merjax_update_pr and merjax_merge_pr. It does not explicitly contrast with the closest read sibling, merjax_list_prs, which is an unfiltered listing, so the differentiation is implicit rather than stated.

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?

Usage is only implied: an agent can infer this is the tool for keyword-driven PR lookup versus browsing. There is no explicit statement of when to prefer merjax_list_prs, merjax_get_pr, or merjax_search_issues, and no prerequisites or exclusions are given.

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