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

Annotations already declare readOnly, idempotent, non-destructive, and non-open-world behavior. The description adds useful context beyond annotations: accent-insensitive matching, the result fields returned, and a credit cost of 1. It does not discuss pagination or limit behavior, but the schema covers that.

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 compact sentences, front-loaded with the primary use case and followed by return details and cost. Every sentence adds practical information with no repetition or filler.

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 simple read-only search tool with a full output schema and annotations, the description supplies the remaining practical context: lookup purpose, accent tolerance, returned fields, and credit cost. No critical agent-facing information is missing.

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 four parameters. The description adds only marginal meaning, such as noting that accents are optional, but does not elaborate on query format, league filtering, or weight-class behavior beyond the schema.

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 and resource ('find a fighter's id by name or nickname') and clarifies the tool's role relative to siblings like get_fighter by focusing on lookup rather than full profile retrieval. The result fields are also named, making the tool's output purpose clear.

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?

Explicitly says to use it to find a fighter's id by name or nickname, which gives clear context for when to call it. It does not explicitly name alternatives or exclusions (e.g., 'use get_fighter once you have the id'), so it stops 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.