entity_update

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

Annotations indicate readOnlyHint=false, so the write nature is known. The description adds valuable behavioral context: it upserts ('Creates the entity if it doesn't exist'), stores structured operational state, and explains the context_hint rejection mechanism that prevents cross-project contamination. This goes beyond the annotations.

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 front-loaded with 'Use this' and consists of five sentences, each earning its place: purpose, trigger phrases, upsert behavior, stored fields, and timing. No redundancy or filler.

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?

Given the tool's complexity (3 params, nested updates object, no output schema), the description covers purpose, triggers, timing, and an important safety behavior (context_hint validation). It does not describe return values or error handling in general, but the core usage context is complete enough for an agent to select and invoke the tool correctly.

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 100%, with each parameter already documented. The description lists field categories (status, momentum, blockers, next move, decisions) which loosely maps to schema properties but adds no new parameter-level meaning beyond what the schema provides. Baseline 3 is appropriate.

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 clearly states the tool's verb ('add or update') and resource ('project, product, or business idea in Brain OS'), and distinguishes it from built-in memory. It also provides trigger phrases ('add project X', 'track X') and notes the upsert behavior, making the purpose unambiguous and differentiated.

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?

The description gives explicit when-to-use triggers: user phrases and timing ('after work is done, a decision is made, a blocker changes, or momentum shifts'). It mentions 'not built-in memory' as an alternative but does not explicitly exclude other sibling tools like entity_read or plan_add, so it falls short of full when/where-not guidance.

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