update_github_project_item_field

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

Annotations already declare the safety profile (readOnly=false, destructive=false, idempotent=true, openWorld=true). The description adds non-obvious operational context the annotations do not carry: the tool is disabled by default and requires an explicit Project allowlist, and it writes exactly one field per call. It stops short of describing failure modes or what non-target fields are left untouched.

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 sentences, no filler, with the scope of the mutation front-loaded and the enablement caveat immediately after. Every clause earns its place.

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 mutation tool with no output schema and a mutually exclusive nested value object, the description covers the essentials: what gets written, the accepted value shapes, and the allowlist gate. Remaining gaps are the ID semantics for the three required identifiers and confirmation of whether multiple value branches may be combined.

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% across four required parameters and a six-branch nested value object, so the description carries real weight here. Its list of field types (text, number, date, single-select, multi-select, iteration) maps usefully onto the value object's keys, but projectId/itemId/fieldId are never explained (ID format, source of the IDs) and the one-key-per-call constraint on value is only implicit in "one ... field".

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 gives a specific verb (Update) plus resource (one field on a Project v2 item) and enumerates the field types it handles, which is more precise than a generic "update project item". It does not explicitly name its near siblings (update_github_project_item_status, update_github_project_item_priority), so an agent must infer the split from the field-type list rather than being routed.

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?

Usage is only implied: the field-type enumeration suggests this tool is the generic escape hatch when a dedicated sibling (status/priority) does not apply, but that is never stated. The availability precondition ("Disabled by default and requires an explicit Project allowlist") is a real gating signal but not an alternative-selection rule.

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