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

Annotations declare destructiveHint=true, non-idempotent, non-readonly, so the write/destructive profile is already known. The description adds that it settles matches via score/status, but says nothing about what gets overwritten, permission/auth needs, or irreversibility beyond the annotation. It does not contradict the 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?

One short sentence, front-loaded with the verb and resource. Minimal but coherent; it earns its place without waste, though it is arguably too sparse given the tool's complexity.

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?

A destructive, non-idempotent mutation with 6 params and no output schema needs more: it doesn't explain the optional params (court, winner, away_score/home_score) interaction, nor what happens on walkover vs finished status. Annotations cover safety but the description leaves meaningful behavioral gaps for an agent to call it 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 description coverage is 100%, so the schema already documents all 6 parameters including the enum-like status list. The description mentions only score and status, adding no syntax or format detail beyond the schema. Baseline 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?

Clear verb (Update) + resource (fixture) + fields (score, status), and parenthetical 'settle a match' adds domain context. It distinguishes from the read siblings get_fixture/list_fixtures, though it doesn't explicitly contrast with other mutation tools. Specific enough for an agent to select over reads.

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 parenthetical hints at settling a match, but there is no explicit when-to-use vs alternatives, no prerequisites (e.g., fixture must be live/ready), and no when-not-to-use. Sibling routing is left entirely to inference.

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