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

With no annotations provided, the description carries the burden of behavioral disclosure, and it does so well: it explains empty-value clearing semantics, validation rules, and atomic failure behavior. It stops short of mentioning permissions, side effects, or whether unspecified fields are left untouched, so it is not fully transparent.

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 a concrete usage pattern and then adds necessary edge-case semantics in a compact, well-organized way. Every sentence carries information relevant to correct invocation, with no filler or repetition.

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 two-parameter tool with fully documented parameters and no output schema, the description covers the main invocation details: syntax, value formats, clearing behavior, and failure modes. It is slightly incomplete because it does not state whether unspecified fields are preserved or reset, and gives no success-response expectations.

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 baseline is 3. The description adds meaningful value beyond the schema by clarifying country-code alternatives, empty-value clearing semantics, and the all-or-nothing failure behavior, which helps an agent construct values correctly.

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 uses a specific verb ('Fill in') and a precise resource ('a project's own columns on one issue'), and distinguishes it from general issue updates by emphasizing custom project columns and field-name-based input. This clearly separates it from siblings like update_issue and set_project_field.

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 clear context: use this when setting project-specific columns on a single issue by field name. It does not explicitly name alternatives or state when not to use it, but the scope is specific enough that an agent can infer the intended use case.

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