update_pr

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

With no annotations, the description carries the burden. It discloses that null values are ignored, that updates are partial, that merged PRs cannot be updated, and specifies the return format. This is thorough for a simple update tool, though it omits permissions or rate limits.

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 short and well-structured: an introductory sentence, a bulleted list of optional updates, a returns line, and a note. Every sentence adds value, and the key purpose is front-loaded.

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?

Given the tool's complexity (7 parameters, no annotations, but output schema exists), the description covers core functionality well: update behavior, optional fields, constraint on merged PRs, and return format. Some context is missing (owner/repo, authentication), but it is largely sufficient for correct usage.

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?

The description explains the main optional parameters (title, body, base, state) with their meanings and state values, compensating for the 0% schema coverage. However, it fails to mention the owner and repo parameters, which are present in the schema with defaults but could be important for context.

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 states 'Update PR metadata' and specifies that only provided fields are updated, distinguishing it from sibling tools like merge_pr (merging) and create_pr_with_content (creating). It lists the optional fields and their meanings, making the purpose explicit.

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 provides guidance on when to use the tool by stating 'Only provided fields are updated; None values ignored' and 'Cannot update merged PRs.' It implicitly differentiates from siblings through context, but lacks explicit 'use this instead of' statements.

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