get_sector_overview

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered; the description instead adds the response-format contract and the failure behavior for an unknown industry key ('returns a short message listing the valid ones'). That error-path disclosure is genuinely useful and not present in the schema. It stops short of stating data freshness or caching for market cap/weights, which matters for a market-data tool.

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?

Three short paragraphs ordered as what-you-get, when-to-use, and how-it-behaves, with no filler sentences. The format and error-behavior notes are compact and come after the high-value content.

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?

Output schema exists and annotations cover the safety profile, so the description's job is to explain payload shape, call order, and edge cases -- and it does all three, including the unknown-industry-key path. Nothing needed to invoke this correctly in a two-step workflow 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 coverage is 100% and the schema already spells out the sector enum, the industry key examples, and the 'call once without it' instruction, so the description largely restates structured data. It adds the two-step discovery semantics but says nothing about the limit parameter (rows per company list, 1-50) beyond what the schema states. Baseline 3 is appropriate when the schema carries the parameter burden.

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 first sentence names a specific resource and its two modes ('Overview of a market sector, or of one industry inside it') and enumerates exactly what is returned: description, company count, market cap, market weight, largest companies with analyst rating. The second sentence refines the distinction between sector-level and industry-level payloads (industry keys/weights vs. growth and performance lists), which no sibling tool offers.

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 gives concrete use cases (sector rotation, 'biggest semiconductor companies', finding peers, exploring an industry before picking names) and an explicit call sequence: call without industry first, then pass one of the returned keys. That sequencing rule removes the main failure mode an agent would hit with the optional industry parameter.

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