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

Annotations already declare the safe-read profile (readOnly, idempotent, openWorld, non-destructive), so the bar is lower. The description nonetheless adds real behavioral context: revisions are immutable, and "Missing coverage is not zero" warns that absent KPIs must not be read as zero values. It stops short of explaining pagination or the effect of includeRevisions.

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 dense sentences, front-loaded with the returned resource and its characteristics. Every clause carries information; the trailing caveat about missing coverage earns its place. Slightly terse given the number of parameters left undiscussed.

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 8 parameters, 0% schema coverage, and no output schema, the description should say more about the temporal filters and revision flag. The safety profile is covered by annotations and the null-means-not-zero caveat is valuable, but an agent still lacks enough to invoke the filters confidently.

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% across 8 parameters, so the description carries the burden. It hints at several params (accounting basis -> basis, fiscal periods -> from/to, immutable revisions -> includeRevisions) but leaves asOf, limit, and the metric identifier format unexplained. It partially compensates, not fully.

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 resource: company-disclosed operating KPI observations, with the fields they carry (fiscal periods, native currency, accounting basis, scope, evidence). This distinguishes it implicitly from siblings like company.financials and company.statements, though it never names an alternative explicitly.

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?

No when-to-use, when-not-to-use, or alternative-referencing guidance. The agent must infer from the sibling list that financials/statements cover reported financials while this covers operating KPIs. Nothing tells the agent when this tool is the right pick.

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