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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuine context beyond that: the scope is limited to *published* instruments, and it discloses a return element (checkUrl as a shareable link), which is not in any structured field.

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 tight sentences with the search capability front-loaded and the return-value note second. 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?

With no output schema, the description helpfully names the key return field (checkUrl). It stops short of describing result shape, ordering, or what 'limit' controls, which leaves a small but real gap for a search tool.

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 burden. It does explain that 'query' spans name, ISIN, or ticker, but says nothing about the 'limit' parameter, defaults, or the 1-20 cap. Partial compensation for a real gap.

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 (search) plus the exact resource (published instrument catalogue) and enumerates the searchable key types (name, ISIN, ticker). This is clearly a free-text catalogue search, distinct from the analytical siblings compare_funds, rank_funds, and xray_portfolio.

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?

Usage is implied by 'search the catalogue', but there is no explicit statement of when to use this versus compare_funds or rank_funds, nor any prerequisites or exclusions. An agent can infer the lookup role but must reason about routing itself.

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