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

The description discloses meaningful behavioral context beyond the readOnlyHint and openWorldHint annotations: the tool is keyless, works only against public GitHub metadata, never accesses private repos, incurs a specific $0.01 USDC payment on Base, and provides a payTo address. This is genuinely useful operational transparency about auth, data scope, and cost.

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 dense and front-loaded, packing the tool's purpose, modes, parameter rules, auth constraints, cost, and payment address into a compact block. Every clause earns its place, though the telegraphic run-on style could be better structured for readability.

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 no output schema, the description covers the main invocation details: modes, required parameter combinations, keyless public access, and payment information. It does not describe the response shape or clarify how the $0.01 USDC payment is handled or verified, which leaves a small but real operational ambiguity.

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?

Although the schema covers all parameters, the description adds critical cross-parameter semantics that the schema does not explicitly provide: which parameters belong to which mode, the mode combinations (e.g., owner=&repo= vs full=owner/repo), and the default mode. This goes well beyond the individual field descriptions.

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 clearly identifies the tool as a GitHub public REST lookup via api.github.com, with explicit modes (search, repo, user) and a default. It is specific about the resource and verb, and the GitHub domain distinguishes it from all listed sibling tools, none of which are GitHub-focused.

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 gives explicit mode-to-parameter mappings: search uses q, repo uses owner=&repo= or full=owner/repo, and user uses user= or login=. It also states the public-only scope and that no private repos or token are supported. It lacks an explicit statement about when to prefer an alternative, but no sibling tool provides overlapping GitHub functionality.

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