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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered; the description adds genuine value by stating retention behavior ('nothing is deleted') and the exact fields returned, which annotations cannot express. Minor gap: no ordering or pagination behavior for a potentially long version list.

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?

One dense sentence with zero filler, front-loading the scope ('every version ... for an ISIN') before the returned fields. Slightly telegraphic phrasing ('its path under tm/') but nothing is wasted.

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 one-parameter read with no output schema, the description covers scope, retention semantics, and the returned field set — enough to call it correctly. Ordering/limit behavior is the only meaningful omission.

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% and the single subject parameter is fully documented in-schema, including the TEST namespace convention. The description only restates 'for an ISIN', adding nothing beyond the schema, so the baseline 3 applies.

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?

Names a specific resource (target market statement versions) scoped to an ISIN and even enumerates the returned fields (filed_at, supersedes, tm/ path, sha256). It doesn't explicitly contrast with the singular get_target_market sibling, so it stops short of a 5.

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?

'Every version' and 'nothing is deleted' imply the historical/audit use case, letting an agent infer this is the versioned counterpart to get_target_market. There is no explicit when-to-use or when-not-to-use statement naming an alternative.

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