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

Adds substantial context beyond the annotations: removal of the zone's external-dns happens asynchronously on the next pass, existing records in the zone are left untouched (consistent with destructiveHint=false), and credentials.write is required. This tells the agent what actually changes and what does not, which the bare annotations cannot convey.

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?

Three tight sentences, front-loaded with the core action, then the side-effect, then the scope exclusion and auth requirement. Every sentence carries information an agent needs, with no filler or restatement of the name.

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, the description covers the effect, the non-effect on records, the scope boundary, and the credential requirement. It stops short of stating whether repeated invocation is safe or what happens to a zone that does not exist, gaps that matter slightly given idempotentHint=false.

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 zone, cluster_id, and cluster_name are already documented; the description adds no syntax, format, or targeting nuance beyond what the schema provides. Baseline 3 applies when the schema does the heavy lifting.

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?

Names a specific verb (withdraw/remove) and a precisely scoped resource (a DNS zone declared by a cluster), immediately disambiguating it from the organisation-wide variant. An agent can tell what this does versus add_cluster_custom_dns_zone or list_cluster_custom_dns_zones without opening schemas.

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?

It states the exclusion clearly ('An organisation-wide zone is withdrawn with `ankra org custom-dns-zones remove`, not here'), which is the most likely mix-up. However, the named alternative is a CLI command rather than an invocable sibling MCP tool, so the routing value is partial and no explicit when-to-use trigger beyond the operation itself is given.

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