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

Annotations already establish that this is a safe, read-only, open-world lookup, so the safety profile is covered. The description does add genuinely useful non-annotation context: that completed lookups cost credits and that repeated requests may purchase the same data again. But the cost disclosure is internally inconsistent ('at least 10 Nexscope credits' versus '1 credit per request'), which weakens what would otherwise be a strong behavioral signal.

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 core two sentences are well front-loaded, but the tail is pasted supplier marketing copy ('GitHub Contributions API View Pricing Get a user's GitHub contribution graph for a year. 1 credit per request Actual supplier units are reported per request. Examples are not guaranteed prices.') that repeats the purpose and contradicts the earlier credit figure. A reader must wade through duplicated pricing boilerplate to extract the real constraints.

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?

There is no output schema, and the description compensates by naming the return contents (total contributions plus daily counts/intensity). Inputs, defaults, and cost implications are all covered for a low-complexity, three-optional-parameter read lookup. The only shortfall is the unresolved credit-cost inconsistency and the missing distinction from the user_activity sibling.

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%, so all three parameters (url, year, handle) are already documented, including the current-year default. The description restates the handle-or-URL input path but adds no format examples, no note on precedence when both handle and url are supplied, and no validation constraints. Baseline 3 is appropriate when the schema carries the semantics.

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 names a specific verb and resource: retrieve a user's public GitHub contribution graph for a year, with total contributions and daily counts/intensity. That is clearly distinguishable from siblings like social_github_user_repositories or social_github_user_pull_requests. It stops short of explicitly contrasting with the closest sibling, social_github_user_activity, which also reports user activity.

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?

It gives input-selection guidance ('Pass github handle, or a full GitHub profile url') and a default ('Defaults to the current year'), which is practically useful. However, it never says when this tool is the right choice versus social_github_user_activity or social_github_user, and there are no exclusions or prerequisites. Usage is implied by the resource name rather than stated.

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