store_update

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

Despite the annotations providing three hints (non-readOnly, non-openWorld, non-destructive), the description adds substantial behavioral context: the exact error contract for unknown IDs, the return value shape, the mutation of updated_at, retention of audit metadata, and scope confinement. The description goes beyond the annotations without contradicting them.

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 entire contract is four sentences you could fit in the front half of one textual phrase: purpose, key constraint with error, deviation semantics, return value, and scope. Every sentence contributes new information and the formatting uses internal sentence length well to carry the precise semantics of the nested error case. No fluff.

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 mild-mutating store tool, the description covers the essential ground: mutation semantics, error semantics, return value, and scope. Given there is no output schema and 0% schema coverage, the description does nearly all the lifting and does so well. It could add clarity about partial-vs-full record replacement semantics and what 'confined to your store_scope' means in practice for cross-scope agents, but this is a minor gap.

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%, so the burden falls on the description. It explicitly explains the `deviation` parameter ('declares pattern-departure exactly as in store_put') and gives a clear model for `record` via 'Replace existing record's data'. However, app_id, collection, and record_id semantics are only implicitly captured through the main action sentence, and the nested `record` structure gets little detailed treatment.

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 action ('Replace an existing record's data in-place') with the precise scope of behavior: same ID, updated_at bumped, audit metadata retained. It explicitly contrasts with the create path ('use store_put to create'), distinguishing it from its closest sibling without any ambiguity. This is about as clear as it gets.

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 tells the agent exactly when to use this tool and when not to: 'Never creates: an unknown ID returns {error: not_found} (use store_put to create)' — an explicit when-not-to plus the named alternative. It also injects the operational constraint 'Confined to your store_scope'. This is explicit exclude-and-redirect guidance with no inference required.

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