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

Annotations already mark it as read-only, idempotent, and non-destructive. The description adds that it requires the PRO plan, an access constraint not covered by annotations. It also clarifies the event categories, but doesn't discuss ordering or pagination behavior beyond what the schema's limit parameter implies.

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 a single concise sentence with an added access constraint, immediately front-loading the tool's purpose. No redundant 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?

With an output schema present, return values need not be described. The description covers the event types and the PRO plan requirement; combined with parameter descriptions and annotations, the tool is fully contextualized for a straightforward read-only operation.

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 input schema contains descriptions for both parameters (100% coverage), so the description adds no additional semantic value for match_id or limit. The baseline score of 3 applies as the schema sufficiently documents parameters.

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 the tool provides a timeline of events for a match, listing specific event types (breaks, games won, sets won, momentum runs). This differentiates it from sibling tools like get_match or get_match_score, which likely provide summary or score data.

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 context that this tool is for timeline events, but does not explicitly instruct when to use it over alternatives. There is no mention of when not to use it or which sibling tool to choose for other needs, so guidance is implied rather than explicit.

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