GitHub

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

Annotations already establish readOnly/idempotent/non-destructive/openWorld, and the description adds genuinely new behavior: per-call credit charging, the result reporting charged and remaining credits, failures being free, and the free cache window. It also discloses pagination mechanics ("List resources return a `cursor`: pass it back unchanged for the next page"). None of this is derivable from the annotations.

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?

Front-loaded with the operating rules before the resource list, and the per-resource bullet format is easy to scan. Minor waste: the opening sentence partly duplicates the resource list, and "1 credit." is repeated on all ten lines instead of being stated once.

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 ten-parameter dispatcher with a nested free-form `params` object and no output schema, the description covers routing, identifiers, cost, caching, and pagination well. It is slightly thin on what the result object contains per resource and defers detailed param types to `describe` rather than explaining them inline.

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 100%, so the baseline is 3, but the description adds real meaning by mapping required identifiers to each resource (url|repo, handle|url) and listing per-resource optionals such as `since`, `state`, `year`, `type`, `direction`. It does not cover every schema param (e.g. `sort` for user.repositories and `language` for trending are only in the schema), which keeps it from a 5.

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?

Opens with a specific verb+resource statement ("Data from GitHub: profiles, repositories, contribution history, activity, pull requests") and then enumerates ten named resources with their required identifiers, so an agent knows exactly what surface this tool covers. It is trivially distinguishable from platform siblings like twitter, reddit, or linkedin.

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 concrete operating instructions: pick a `resource`, pass its params as top-level args, put extras in `params`, and call `describe` when types or allowed values are unclear. Also states that failures are free and that passing `max_age_days` yields a free cached copy, which is actionable cost guidance. It stops short of stating when NOT to use this tool or when a sibling (e.g. search) is preferable, so it is a 4 rather than a 5.

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