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

Annotations already cover readOnly/idempotent/non-destructive/closed-world. The description adds genuinely new behavior: Austria-only gating, the failure mode for German ids, the prefixed company_id in the response, and a recency caveat on peers. It does not discuss rate limits or pagination, but the added context is substantial.

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?

Front-loaded with purpose, then bulleted parameters, then return/alternative notes; every section earns its place. Slightly long for a two-parameter tool, but no filler sentences.

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?

An output schema exists, so the description needn't detail return values, yet it still flags country, prefixed company_id, percentiles and the peer recency note. Combined with error behavior and the sibling alternative, an agent has everything needed to call it correctly.

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 load, and it does: company_id format "AT:{fnr}" with bare FNR accepted and a country constraint, plus n's meaning as nearest-peer count with default 10. Both parameters are fully specified.

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+resource ("Benchmark ONE company against its size-class cohort") and enumerates the outputs (headline metrics, percentile ranks, nearest peers). The emphasis on "ONE" implicitly distinguishes it from the multi-company/peer-set siblings.

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?

Gives clear context: Austria only, requires parsed financials, German ids error out, and routes cross-border intent to find_peers with cross_border=true. It lacks an explicit when-not-to-use this for domestic list-building, but the alternative is named with its selecting condition.

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