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

Annotations already declare the safety profile (not read-only, not destructive, not idempotent), so the bar is lower. The description adds genuinely new behavior: the operation fails on slug collision, and uniqueness is scoped per tenant — neither is visible in annotations. It is silent on permissions and on whether the old slug keeps resolving, which keeps it short of a 5.

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 tight sentences with zero filler, and the core operation is front-loaded before the failure condition. Every clause carries information an agent would not otherwise have.

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 mutation with full annotation coverage and an output schema, the description covers what it does and the one failure path. Only the permission/prerequisite dimension and the fate of the old slug are left unstated.

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 both parameters are already documented, including the hierarchical path segment allowance. The description only echoes the per-tenant uniqueness constraint already stated in the new_slug schema text, adding no syntax, format, or validation guidance beyond it.

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?

States a specific verb (rename) and a precisely bounded resource (a schedule's slug), plus a parenthetical defining what a slug is. It is distinguishable from rename_app_slug by resource, but it never addresses the closest ambiguous sibling, update_schedule, which could plausibly also change a slug.

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 by the narrowness of the operation; there is no explicit statement of when to call this versus update_schedule or when a slug change is the wrong fix. The one conditional sentence describes a failure mode, not a selection rule.

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