get_amendment_diff

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

Annotations already declare readOnly, idempotent, non-destructive, so safety is covered. The description adds real behavioral context beyond that: the output fields, the sort order (|diff_pct| desc), and the default materiality filter. It stops short of noting pagination or result-size limits.

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-loaded with the core definition, then differentiation, then examples — a clean structure with no filler. Slightly dense but every sentence earns its place.

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?

With an output schema present, return values needn't be detailed. The description covers purpose, sibling differentiation, filters, and use cases; only the unexplained entity_id/fiscal_year semantics leave a minor gap.

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 0%, so the description must carry the burden. It explains min_diff_pct (default 1%) and maps hub_concept_code and kind, but leaves entity_id and fiscal_year unexplained beyond an inferable 'FY24' example. Partial compensation only.

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+resource with the exact output shape (old_value, new_value, diff_pct, kind) and scope (all 10-K/A amendments of an entity). It explicitly distinguishes itself from the sibling get_amendments, so an agent can route 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 contrasts with get_amendments ('which returns counts per amendment') and states when to use it via three concrete example queries (specific FY change, all REVENUE restatements, material corrections only). Both when-to-use and the alternative are covered.

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