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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real behavioral detail beyond that: the response discloses which ranking method was used, and the computation is bounded to 'only the company counts, deal size and percentages you give' — a meaningful determinism claim.

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?

Purpose is front-loaded ('Select a beachhead market'), followed by the conditional behavior. It is dense and delivered as one long semicolon-chained sentence, but each clause carries information about inputs or method selection rather than filler.

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?

For a 10-parameter tool with no output schema, the description covers the flow and method selection but never characterizes the return payload (what the ranked segments or TAM/SAM/SOM output looks like). Annotations cover the safety profile, but the result format remains undocumented anywhere.

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 the schema already documents all ten parameters individually, including the sales_cycle caveat and the range refusal. The description restates the customer_pain/current_customers/average_deal_size interaction that the schema also states, adding little new semantics, so the baseline 3 is appropriate.

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 states a specific verb and resource: 'Select a beachhead market', and adds the two concrete outputs (ranked segments and a TAM/SAM/SOM calculation). It is clearly distinguishable from strategy-analysis siblings, though it never names an alternative to route against.

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 explains the internal method switch ('when you give all three... otherwise keyword presets') and which inputs feed the sizing, which is useful context. However, it gives no guidance on when to pick this tool over impact_full_audit or impact_pinpoint_value, so tool-level selection is left to inference.

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