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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds real behavioral context: omitting the section returns only the index with no text, and requesting one returns text capped at 20,000 characters with original length and a truncation flag. It does not mention rate limits, auth needs, or how the 20k cap interacts with max_characters.

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 sentences, front-loaded with the usage trigger and followed immediately by return-behavior details. No filler, no restatement of the name or title.

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 need not be described, yet the description still covers the meaningful output behaviors (truncation, index-vs-text). The only real gap is that max_characters is not surfaced as a tunable parameter, which an agent would need to know to request less than the full text.

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 load. It usefully explains the provenance of filing_id (from list_filings) and the behavioral meaning of omitting section, but max_characters is never named as an adjustable input despite the description hinting at a 20,000-character ceiling; the default of 12,000 is unmentioned.

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 states a concrete verb and resource ('read what a filing says in one section') plus a second mode (returning the section index), which is far more specific than the title. It references list_filings as the source of the filing id but does not distinguish this tool from filing_facts or compare_filing, so sibling differentiation is partial.

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?

'Use when someone asks what a filing says in one section, such as risk factors or the business description, or wants the list of sections' gives a clear triggering context and concrete examples. It lacks explicit when-not-to-use guidance or a named alternative among the siblings.

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