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

Annotations already carry the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the description is not required to state that it is a safe read. It adds genuinely new context: the brain:read permission requirement and a full enumeration of what the payload contains, including the status vocabulary and that failures carry a reason.

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 dense sentence, front-loaded with the resource and selector before the payload details. The field enumeration is long but earns its place given there is no output schema; nothing is redundant.

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 no output schema and zero schema coverage, the description usefully documents the return shape — note, status states, and per-item fields (kind, key, locale, current/proposed value, rationale, confidence, status). The one missing piece is any explanation of startupId, which leaves a real gap for a two-parameter 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 description coverage is 0% for two parameters, so the description bears the full burden. It gives meaning to the required 'id' only implicitly ('by id'), and the second parameter, startupId, is never mentioned in either the schema or the description — the agent has no way to know whether it is required, optional, or what it scopes.

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 identifies a specific resource ('one revision of the company brain') and a specific selector ('by id'), which is enough to separate it from getfund_brain_revise (creating a revision) and getfund_brain_apply_revision (applying one). The verb is nominalized rather than stated ('fetch'/'get' is implied), but the retrieval intent is unambiguous.

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 phrasing 'one revision ... by id' tells the agent this is the single-item reader, and 'Needs brain:read' gives a permission precondition. There is no explicit statement of when to call this versus getfund_brain or getfund_brain_apply_revision, and no note that the id must come from a prior revise call.

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