Trending instruments

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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, so the safety profile is covered. The description adds genuinely non-structured behaviour: results are ranked 'most trending first' and mirror the app's Explore tab ordering, plus the returned field set. It does not discuss freshness or refresh cadence, which would be the remaining piece.

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?

A single sentence that front-loads the core purpose and ordering, then names the returned fields, then the alternative tool. No filler, nothing repeated from structured fields.

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 usefully enumerates what is returned (ticker, name, asset class, sector) and the ranking semantics, which is what an agent needs to decide relevance. Missing only minor operational detail such as default limit behaviour, which the schema carries.

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 the parameters are already documented and a baseline of 3 applies. Note the description's market list ('Egypt, US or UAE') omits the 'simulator' enum value that the schema includes, so it adds no meaning beyond the schema and is slightly narrower than it.

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?

Specific verb+resource with scope: it states the tool returns instruments trending on Thndr per market, in rank order, matching the Explore tab, and enumerates the returned fields. An agent can distinguish it from price-serving siblings at a glance.

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?

It explicitly routes the agent elsewhere for prices ('Use get_price_snapshot for their prices'), which is a real alternative-selection cue. It gives no explicit when-not guidance relative to near-neighbours like get_market_movers, so it stops short of the top band.

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