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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds a genuine trait beyond them: 'Public.' (no authentication needed), plus clarifies the data scope is the calendar rather than the report pillar. It does not describe ordering or return shape, but the annotation bar is lower.

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 short sentences, front-loaded with what it lists, then the optional filter, then the critical disambiguation. No filler and no repetition of structured data beyond a brief market mention.

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 listing tool with no output schema and full annotation coverage, the description supplies the essential scope and sibling routing. It is nearly complete, though it could note ordering or whether results are time-bounded.

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% – both limit (default 12, max 40) and market are fully documented in the schema. The description only restates 'Optional market filter', adding no syntax or semantics beyond it, so the baseline of 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?

States a specific verb (list) and resource (shows, auctions, and other gatherings on the Attic calendar), and explicitly distinguishes itself from the similarly named Gatherings pillar by naming the sibling tool attic_get_market_report. An agent can disambiguate without opening either schema.

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 states the alternative for the clashing case: 'not the Gatherings pillar of the weekly report (use attic_get_market_report with pillar gatherings for that top 5).' This is a when-not plus a named substitute, which is the strongest form of routing guidance.

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