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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds real value beyond them: the FREE tier, the exact status semantics tied to an external calendar, SPAC exclusion, and the sort order (expected date, undated last). Only auth/rate-limit behavior is unstated, which is minor for a free read-only listing.

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?

Front-loads 'FREE' and the core scope, then fields, exclusions, follow-ups, and arguments in a logical order. Dense but each sentence carries information; the field enumeration is slightly long, though it substitutes for output-schema reading.

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?

Covers scope, exclusion rules, status values, defaults, sorting, and escalation paths, and an output schema already handles return structure. An agent has everything needed to call it correctly and interpret the results.

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 coverage is 100%, so the baseline is 3, but the description goes further by restating defaults (status=upcoming, since=one year ago, limit=100/max 500) and clarifying that since only applies to withdrawn/postponed. It also adds ordering behavior that the schema does not express.

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?

Opens with a specific verb/resource and scope: operating companies that filed with the SEC but aren't trading yet, plus withdrawn/postponed deals. It distinguishes itself from siblings by naming get_ipo_filings and get_ipo_snapshot as follow-ups, so an agent can route without opening schemas.

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?

Explicit when-to-use ('see what is coming to market or what was pulled') plus a clear exclusion (SPACs and other vehicles are excluded because it mirrors the iposignal.xyz calendar) and named alternatives for deeper dives. Nothing is left to inference.

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