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

Annotations already declare the write/idempotent/non-destructive profile, but the description adds real context beyond them: it explains the workflow split (assistant interprets, Brix36 validates and stores), states what happens on collision ('Duplicate category/sentence on the same attachment is reused'), and discloses cost and side effects ('Free; no server language model is called'). That is meaningful transparency over the structured hints.

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?

Four sentences, front-loaded with the purpose, then workflow, return, collision behavior, and cost. Each sentence carries information, though 'Returns an approved user-authored fact' and the Brix36 storage sentence overlap somewhat and could be merged.

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 small 4-parameter, all-required write tool with an output schema and full schema coverage, the description supplies the essential missing pieces: the validate/store workflow, idempotent reuse semantics, and zero-cost behavior. Nothing critical is absent for correct invocation.

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 the schema already documents all four parameters with length bounds and ID provenance. The description only loosely references category/statement/attachment ('category/sentence on the same attachment') and adds no format or constraint detail beyond the schema. Baseline 3 applies when the schema does the work.

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: 'Save one concrete creative instruction about a customer reference already on this project.' The scope (reference already on the project) is clear. However, it never names its closest siblings (studio_reference_note_update, studio_reference_notes_list, studio_reference_add), so the agent must infer the distinction from the title.

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 implies when to use it ('one customer-approved instruction grounded in an uploaded reference' per the schema, plus 'the connected assistant does the interpretation with the customer'), but it offers no explicit when-not-to-use or pointer to the update/list/add siblings. Usage is inferable rather than stated.

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