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

Annotations already declare read-only and idempotent behavior. The description goes further by disclosing the exact matching criteria (same CIK, 90-day window), the meaning of the status categories, and the key insight about expired notices with no sale. This is rich behavioral context beyond what annotations provide, and there is no contradiction.

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?

Two dense, information-packed sentences. The opening phrase 'Cross-feed signal' immediately sets the tool apart. Every clause earns its place, with no redundancy or 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?

For a complex cross-feed tool with no output schema, the description gives a solid conceptual overview, including what it surfaces (execution ratios, never-executed sales) and the matching logic. However, it does not describe the response structure or pagination details beyond the schema, and given the tool's complexity, a bit more about return format would complete the picture.

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 100%, so the baseline is 3. The description reinforces concepts like 'not_executed' and 'unverifiable', but it does not add syntax or format details beyond what the schema already provides. It adds narrative context but not parameter-specific semantics.

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 uses a specific verb ('pair'), names the exact resources (Form 144 notices, Form 4 executions), and clearly states the output (execution ratios, announced-but-never-executed sales). It distinguishes itself from sibling tools by emphasizing the 'cross-feed' nature and that raw EDGAR cannot answer this in one query.

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 clearly implies when to use this tool (when comparing planned vs executed insider sales) and provides context about the matching logic. However, it does not explicitly name alternative tools such as get_planned_sales or get_insider_trades, nor does it state when-not-to-use it, so it falls short of a 5.

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