Extract a setlist ID from a setlist.fm URL

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

Annotations already declare readOnlyHint and idempotentHint, and the description adds valuable context: 'Pure local parsing — no network call' and 'Errors if no ID can be parsed'. It also details input tolerance (http/https, www, trailing slash, etc.) and scoping constraints, enriching the behavioral profile beyond the structured fields.

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 five sentences, each serving a purpose: purpose, output, scope, tolerances, and error handling. It is front-loaded with the primary function and contains no fluff or redundant phrases.

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 parsing tool with one parameter, the description fully covers what it does, when to use it, what it returns, input constraints, and failure modes. It names downstream tools and explicitly states it's a local operation, leaving no critical 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?

With 100% schema coverage, the schema already describes the url parameter well, but the description adds semantics about accepted URL forms, rejected page types, and error behavior. This goes beyond the schema example, giving the agent a richer understanding of the parameter's constraints.

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 verb 'Parse' and the resource 'setlist ID out of a setlist.fm setlist URL', and explicitly distinguishes this utility from sibling tools by focusing on URL-to-ID extraction. It also mentions the output format and downstream use, making the tool's role unambiguous.

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 explains when to use this tool ('paste a link instead of hunting for the ID') and names the downstream tools it feeds into. It also explicitly states exclusions (artist and venue URLs are rejected), which clarifies when not to use it, though it doesn't explicitly list alternative tools for those cases.

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