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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, and the sentence 'Read-only: returns public data and changes nothing' largely repeats them. The one genuinely additive fact is 'Costs 1 credit per request', which gives budget-relevant context not present in annotations, but nothing is said about result caps or paging behaviour beyond what the schema already encodes.

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?

Three short sentences with the purpose front-loaded and the cost signal last. One sentence is partly redundant with the annotations, but nothing is verbose or buried.

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 an 18-parameter, nested-filter search tool with no output schema, the description is thin: it says nothing about how filters combine, whether query is optional, or that results are paginated via cursor. The rich schema compensates for the per-parameter gaps, but behavioural completeness for a tool this complex is only adequate.

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% and every one of the 18 parameters is documented inline, including range semantics, enum meanings and GitHub qualifier mappings. The description adds no parameter meaning on top of that, so the baseline 3 applies.

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 + resource ("Search public GitHub repositories"), which cleanly separates it from siblings like github_search_code, github_search_issues and github_search_users. The word 'public' also signals it is not the same as github_list_repositories, though no sibling is named explicitly.

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?

There is no guidance on when to choose this over github_list_repositories (list your own repos) or github_search_code / github_search_topics when a query spans code or topic entities. The agent must infer the selection rule from the tool name alone.

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