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

Beyond the annotations (destructive, openWorld, non-idempotent), the description discloses required workspace settings permission, agency-entry permission rules, unsupported pinning behavior, the 409 BRAIN_ENTRY_DERIVED condition, null memory_id handling, queued behavior, and idempotency_key retry guidance. This is unusually rich behavioral context.

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?

The description is dense but appropriately sized for a complex mutation tool. It front-loads the core action and then layers permissions, edge cases, and retry behavior, with every sentence adding operational value.

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 high-complexity tool with no output schema, the description covers important error and permission contexts thoroughly. However, it leaves some parameter context implicit, especially id, workspace_id, and brand_id, which an agent must infer from the schema.

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?

With only 36% schema description coverage across 14 parameters, the description must compensate. It enumerates several editable fields (type, title, content, tags, platforms, importance, pinned, valid_until) but does not explain required id, workspace_id, brand_id, or the body/query overrides, so it only partially closes the coverage gap.

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: 'Edit Brain knowledge' and 'Send only the fields to change.' It clearly distinguishes an update operation from creation tools like add_brain_entry, so an agent can identify it as the edit-existing-entry tool without inspecting siblings.

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 specifies when to use the tool ('correct or change' existing Brain knowledge) and when not to use it (derived entries must be changed at their source; agency entries cannot be pinned). It also gives the permission and ownership conditions required for agency entries, which is explicit routing guidance.

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