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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine data-semantics context beyond annotations: the T1-T4 grading scale, the claimed-unverified default confidence, and the corroborated marking for F500-confirmed records. It says nothing about ordering, pagination, or result limits, so it is additive but not rich.

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?

A single sentence, front-loaded with the resource ('Deal tombstones for a startup') followed by a colon and the payload of useful definitional detail. No wasted clauses, though the density of domain terms makes it slightly heavy for one sentence.

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?

There is no output schema, so the description should carry more of the return-value burden than it does. It conveys the semantic content of records (dating, sourcing, T1-T4 grade, confidence, corroborated flag) but says nothing about the shape, ordering, or volume of the response, and gives no usage guidance for a single-parameter lookup tool.

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 single parameter startup_id is documented in the schema with its source ('from search_startups or get_ranking'). The description adds no parameter-level detail at all, so the baseline of 3 for high schema coverage applies.

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 names the resource (deal tombstones for a startup) and defines it concretely: 'dated, sourced public claims of enterprise commercial wins, graded T1 to T4.' That is far more than restating the name, and the sibling tools (get_methodology, get_profile, get_ranking, search_startups) are clearly different resources. It stops short of an explicit verb and never states how it differs from siblings, so it is clear but not maximally discriminating.

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?

Usage is only implied: the description tells the agent what tombstones contain, so an agent can infer it should call this when it wants evidence of enterprise wins for a known startup. There is no explicit when-to-use, when-not-to-use, or routing to an alternative sibling, and no stated prerequisites.

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