add_blackboard_key

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

Annotations already declare the write/non-destructive/non-idempotent profile, so the bar is lower. The description adds real context beyond that: it discloses the save side effect and, via the return contract (already_exists, verified, saved, save_error), reveals duplicate-key handling and persistence outcomes. It does not explicitly explain why the operation is non-idempotent despite the annotation, but the post-condition detail is valuable.

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-part structure front-loads the purpose in one sentence, then documents the return shape. The return block is somewhat verbose but earns its place since no output schema exists. No filler text.

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 four-parameter mutation tool with annotations and no output schema, the definition covers purpose, the save side effect, and a detailed return contract. The main gap is the absence of any when-to-use routing among the many blackboard siblings, but everything needed to invoke the tool correctly is present.

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%, so all four parameters (including the optional instance_synced) are already documented in the schema with allowed key_type values. The description restates key_name/key_type only inside the return shape and adds no format or constraint detail beyond the schema, so baseline 3 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?

States a specific verb and resource: 'Append a key to a UBlackboardData asset and save it.' This clearly separates it from remove_blackboard_key and get_blackboard_keys. It does not, however, name any sibling as an alternative, so the differentiation is implied by the verb rather than stated.

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 never says when to use this tool versus alternatives like set_blackboard_key_subsettings or remove_blackboard_key, nor does it state preconditions. Usage is only implied by the verb 'append' and the asset path requirement.

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