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

Beyond the annotations (readOnly, idempotent, non-destructive), the description discloses key behavioral traits: limit applies after merging, unknown tickers return 404, data is delayed 24 hours via known_at, and no price-derived fields are present. This adds significant context not derivable from annotations alone.

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?

The description is a tight three sentences, each adding essential information: what it does, the limit caveat with alternatives, and error/delay details. It is front-loaded with the primary purpose and contains no filler.

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?

Given the tool's complexity (merging three filing types with a shared limit, error handling, data delay), the description covers all necessary context: result field, row crowding, fallback tools, ticker failure, and timeliness. An output schema exists, so return format details are covered elsewhere.

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 ticker and limit are already documented. The description adds crucial nuance that the limit applies post-merge, affecting how the parameter should be set, and reinforces that ticker is the issuer's symbol. This exceeds the baseline by providing behavioral context for parameter usage.

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 clearly states the tool's function: merging Form 4, Schedule 13D/13G, and Form 144 filings into one time-ordered feed, with explicit mention of the source_form field. It also distinguishes from sibling tools by pointing to dedicated tools for specific filing types, making the purpose unmistakable.

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?

The description provides explicit guidance on when to use this tool versus dedicated alternatives: it warns about Form 4 crowding out rows and advises 'use the dedicated tools for those.' It also includes error behavior (404 for unknown tickers) and data delay, helping the agent decide if this is the right choice.

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