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

Annotations already declare readOnly=true, destructive=false, openWorld=false, so the safety profile is covered. The description adds genuinely new behavioral context beyond them: processing is local retrieval with neural representation and no external LLM, output is source-linked, and a data-handling rule (don't send customer secrets). It does not explain the non-idempotent hint, but overall it adds real value.

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 tight sentences that front-load the purpose and outputs with no filler. The unexplained "MEMBER:" token is wasteful but the rest earns its place.

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 complex tool with 10 undocumented parameters and no output schema, the description describes the deliverable (source-linked plan, evidence, economics) adequately but leaves the full parameter surface unexplained. It is minimally complete about the result, incomplete about the inputs.

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 0% across 10 parameters, so the description must carry the load and largely does not. Only faint inferences are possible: "unit economics" loosely maps to price/budget/fixedCost/variableCost, and "14-day" hints at hours. Required parameter "question", plus skill, stage, customer, and language, receive no explanation at all.

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 ("build") and resource ("14-day validation plan") and enumerates concrete outputs: opposing success/failure evidence, unit economics, and website-upgrade suggestions. This is much clearer than a tautology, but it never explicitly distinguishes itself from the siblings (compare_startup_cases, get_startup_radar, search_startup_cases, startup_preview). The cryptic "MEMBER:" prefix adds no clarity.

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?

There is no when-to-use guidance and no named alternative among the four sibling tools, so an agent cannot tell from the description alone when to build a plan versus comparing, searching, or previewing cases. "Do not send customer secrets" is a constraint, not usage direction.

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