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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint false, openWorldHint false), and the description adds substantial behavior beyond that: the non-obvious linking rule, the self-linking consequence of copy_branch_name, the branch field in results, and the read-permission requirement. No contradiction with 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?

Three front-loaded sentences with the core purpose in the first. The linking-mechanism and permission sentences each earn their place, though the copy_branch_name aside could arguably be tightened. Slightly dense, but no wasted words.

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 one-parameter, read-only, non-destructive list tool, this is complete: the parameter is fully documented in the schema, the linking semantics and permission level are disclosed, and the return content (PRs with branches) is stated. No output schema exists, so the description adequately covers the gap.

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% — the 'issue' parameter is already documented with format examples ('ENG-42, or an issue id'). The description's linking explanation implicitly reinforces that the parameter is an issue identifier, but it adds no new syntax or format detail, so the baseline of 3 applies.

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 title states a specific verb+resource ('List the pull requests linked to an issue') and the description sharpens it further: 'The pull requests Orbit has linked to an issue, with the branch each one is on.' This names the exact scope and the returned content, making it easy to distinguish from siblings like list_issue_comments or list_issue_attachments.

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 useful context — the linking mechanism (a PR names the issue identifier in branch/title/description) and the permission prerequisite ('Requires only the permission to read the issue'). However, it never explicitly addresses when to choose this tool over alternatives or when not to use it; the cross-reference to copy_branch_name is behavior explanation rather than selection guidance.

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