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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description's added value is the cost model: 1 credit per call with a 25 calls/day free-tier cap, which is operationally important and not in any structured field. It stops short of stating result ordering (presumably score-descending) or the meaning of the DNA score itself.

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 short sentences: scope and filters front-loaded, cost disclosure second. Nothing is redundant or buried, and an agent can parse the whole thing at a glance.

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 should say more about what comes back — row shape, sort order, and that level values are Spanish tokens (fuerte/prometedor/mixto/debil) while sector is a contains-match. For a simple read-only ranking call it is adequate, but those gaps matter for correct invocation.

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 every parameter (level, limit, sector, min_score) is already documented in the schema. The description restates the same filters (minimum score, level, sector) without adding format hints, and omits 'limit' entirely, so 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?

The description names a specific verb and resource ('Ranking of 340+ U.S. stocks by Faro DNA score') and adds the available filters, so the operation is unambiguous. It does not name or differentiate against siblings such as stock_dna or quality_dips, which would be needed for 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?

Usage is only implied: the mention of filters suggests a screening/ranking use case, but there is no explicit statement of when to choose this over stock_dna (single-stock detail) or quality_dips. No prerequisites or exclusions are given.

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