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

Annotations confirm mutation (readOnlyHint=false) and non-destructiveness, but the description adds value beyond them: required scope ('repo'), authorization rules per field, that marking ready starts AI review, and that a base change re-runs pull_request CI and disarms auto-merge. These side effects are not derivable from annotations or schema.

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 purpose, then permissions, then side effects, then return shape in four tight sentences. Dense but nearly every clause carries actionable information, though the parenthetical nesting in the draft clause is a touch heavy.

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?

No output schema exists, yet the description documents the result object fields ({number, title, body, baseBranch, headBranch, isDraft, changed, autoMergeDisarmed, url}), plus permissions and side effects – everything an agent needs to call and interpret this correctly.

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 baseline is 3, but the description adds meaning: body clearing via empty string, base changes restricted to open PRs and triggering CI, and the draft flag's permission rule and AI-review consequence. It reinforces rather than duplicates schema text.

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?

States a specific verb ('Edit') and resource ('pull request's') and enumerates exactly which fields are mutable (title, body, base, draft). It also implicitly distinguishes itself from siblings like gluecron_set_pr_draft and gluecron_update_pr_branch by naming the fields and their edge cases.

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 clear conditional guidance: permission rules per field, the draft rule ('the same rule as gluecron_set_pr_draft'), and that base changes only apply to open PRs. It doesn't state explicit when-not-to-use conditions against a direct alternative, so it falls just short of a 5.

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