Github Update Issue

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

Annotations already cover the non-destructive, non-read-only, idempotent nature. The description adds a valuable behavioral trait beyond annotations: it performs a partial update where only supplied fields are changed and unspecified fields keep their current values. This patch-like behavior is important for correct invocation.

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 consists of one concise, front-loaded sentence with no filler. It states the core action and the key partial-update behavior immediately, making it easy for an agent to parse.

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 detailed input schema, the presence of an output schema, and annotations covering safety and idempotency, the description is sufficient. It captures the one non-obvious behavior—partial updates—that the structured fields cannot fully express. Nothing essential is missing for correct invocation.

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 57%, and the schema already documents the optional fields with 'Omit to leave...' guidance. The description's global statement 'Only the fields supplied are sent, the rest keep their current values' reinforces and generalizes the per-parameter semantics, clarifying that null/omitted values mean 'no change.' This adds meaningful context beyond individual schema descriptions.

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 states a specific verb and resource: 'Updates an existing issue.' It clearly differentiates from the sibling github_create_issue by emphasizing 'existing.' It does not explicitly name alternatives, so it stops 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?

The phrase 'existing issue' implies this is not for creating issues, which helps distinguish it from create_issue. However, there is no explicit when-to-use guidance, no mention of alternatives, and no exclusions. The usage context must be inferred by the agent.

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