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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: the merge behavior ('the next describe merges this back in'), the precedence rule ('an annotation's role wins over the inferred one'), and the effect of each key (unit/description added; hidden omits column from summary). It does not cover error handling or idempotency, but it explains the core behavior well.

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 two sentences long, front-loads the primary action, and packs essential information efficiently. Every clause contributes to understanding the tool's purpose and key semantics without redundancy.

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?

The description covers the core functionality, key semantics, and how it interacts with describe. It does not describe the return value, but for a set operation this may be trivial. It also doesn't mention prerequisites like table existence, but given the schema documents required parameters and the description explains behavior, it is sufficiently complete for its complexity.

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 coverage is 100%, so the baseline is 3. The description adds meaning beyond the schema by explaining the effect of each allowed key value ('role wins over the inferred one; unit/description are added; hidden marks a column to omit from a summary'). It also clarifies the column parameter's purpose by saying 'omit for a table-level annotation', which is in the schema but reinforced. This adds value beyond the schema.

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 the action clearly: 'Annotate a declared table or one of its columns'. It specifies the verb and resource, and the mention of 'the next describe merges this back in' hints at its integration with describe, but it does not explicitly name alternative tools to differentiate from. Thus it is clear but not fully distinctive.

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 context that annotations are merged into the next describe, implying usage before describe. However, it does not explicitly state when to use this tool versus other table tools like host.table.schema or host.table.models, nor does it mention exclusions or alternatives. The guidance is implied rather than explicit.

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