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

Annotations cover only openWorldHint=false and destructiveHint=false; no readOnlyHint, so this is a mutation and the description must carry disclosure burden. It usefully clarifies that a status "grants nothing about what may be said," a meaningful semantic boundary, but says nothing about overwrite behavior, permissions, or what happens if status is omitted.

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 sentences, front-loaded with the primary action, with the caveat trailing. The second sentence is slightly cryptic ("only a member can record") but earns its place as a disambiguation.

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 return values need no explanation, but this is a mutation with an optional status field and the description doesn't cover update-vs-insert semantics or the meaning of the enum states. Adequate but leaves real gaps for an agent invoking it.

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?

At 50% schema coverage, the description does add meaning to status ("following on") and establishedAt ("when that was established"), which the schema leaves undocumented. However, it says nothing about the enum values or the relationshipId/companyId pairing, so half the parameters remain unexplained.

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 and resource ("record whether an existing investor is following on, and when"), which maps cleanly onto the status and establishedAt parameters. The second sentence implicitly separates this from capture_what_was_said, though it never names the sibling directly.

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?

"Existing investor" implies the relationship prerequisite, and the note that "what may be said" is a separate decision hints at the alternative tool. But it never explicitly says when to call this instead of fundraising_set_relationship_stage or fundraising_capture_what_was_said.

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