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

Annotations already declare readOnly/openWorld=false/destructive=false, and the description adds substantial context beyond them: coverage is limited to Sweden's register, matching is by LEI or ISIN so rows may include other instruments, only captured publication days exist, and the register is not a complete insider-ownership record. These caveats materially affect how the agent should interpret results.

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 purpose and identifier format are front-loaded, and the routing hint is saved for last, which reads well. It is dense and slightly long, but nearly every clause carries informational weight for interpreting coverage or results.

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?

Although there is no output schema, the description enumerates the returned fields (date, person/role, related person, type, instrument/ISIN, volume, price, currency, source status including amendments) and states the coverage limits. Nothing an agent needs to call or interpret this tool is missing.

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 schema already documents all three parameters. The description restates the MIC:TICKER format and the bare-ticker fallback, which mirrors the schema's own ticker description, so it adds little beyond structured data. Baseline 3 is appropriate.

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 and resource: fetch director/PDMR transactions published by a regulator for one non-US listing, with the exact identifier format (MIC:TICKER). It explicitly distinguishes itself from the US counterpart GetInsiderTransactions, so an agent can route correctly 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?

Gives explicit when-to-use context (non-US listing, coverage in Sweden's Finansinspektionen register) and a named alternative for the US case ('For US Form 4 filings use GetInsiderTransactions'). The boundary between the two tools is unambiguous.

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