filing_diff

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

Annotations already cover readOnly and openWorld, so the description's real contribution is the comparison baseline: latest filing vs the immediately previous one of the same form, at section granularity. That is genuine behavioral information not in the annotations. It does not discuss what happens when no prior filing exists or how sections are aligned, which keeps it below 5.

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 sentence, front-loaded with the operation and scoped in the same breath, with the output categories appended as a compact clause. Nothing is padded.

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?

The output schema and annotations cover return shape and safety, so the description does not need to. What is missing is the operational context an agent would want: behaviour when no prior filing of that form exists, how section names are matched, and how this differs from filing_text and what_changed.

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 75% (company, form, section documented; max_items has no description), so the schema carries most of the load. The description adds no parameter guidance at all — nothing about accepted company identifier forms, valid section names, the 10-K default, or the max_items cap.

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 resource and operation: a section-level diff between a company's latest filing and the prior filing of the same form, with output classes (new, dropped, reworded). Clear enough to act on, but it never names the near neighbours (filing_text for raw text, what_changed for other change queries), so the boundary is inferred rather than declared.

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?

Usage is implied — 'latest versus previous of the same form' tells you this is for period-over-period comparison of one section. There is no explicit when-to-use/when-not guidance and no routing against filing_text or the similarly named what_changed, which is the biggest ambiguity risk here.

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