github_pulls_update

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

Annotations already flag this as a non-read-only, open-world mutation, so the bar is lower; the description adds real value by disclosing the closing mechanism and the draft-status limitation, both of which are behavioral facts not in the schema. It omits whether omitted/null fields leave values unchanged and what auth scope is required, so not a full 5.

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?

Two tight sentences, zero filler, with the core action front-loaded and the two caveats (closing, draft status) following immediately. Every sentence carries information and nothing is repeated from the schema.

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 8-parameter mutation tool with no output schema, the description covers the main behavioral gotchas and lets the fully-documented schema carry parameter detail. The one meaningful gap is whether omitting or nulling a field is a no-op, which an agent editing a PR would want to know.

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 semantic meaning beyond the schema: `state: closed` is the documented path to closing, and the draft-status note clarifies a limit on what parameters can accomplish. The partial-update semantics for null fields remain unexplained, keeping it at 4.

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 and enumerates the mutable fields (title, body, state, base branch), so an agent immediately knows the scope of the operation. Sibling differentiation is implicit via the verb rather than explicit naming of github_pulls_get/list/create, which keeps this just short of a 5.

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 concrete usage guidance for the non-obvious case — closing is done with `state: closed` — and warns that draft status cannot be flipped via REST, which steers the agent away from a wrong call. It does not state prerequisites (e.g. write permission) or when to prefer this over other PR tools, so it stops short of explicit when/when-not alternatives.

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