capability_register

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

The annotations declare readOnlyHint=false and openWorldHint=true, so the detailed safety burden is lower. The description adds real behavioral context: the shared Policy Gateway path, the Safe+readonly+non-blacklist restriction on auto:true, and that suggestions never bulk-register. It still omits what happens on failure, auth/prerequisite needs, or the confirm gate's role.

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?

Brief and front-loaded, leading with the core action before the constraints. The telegraphic phrasing ('Suggest never bulk-registers') is terse but each sentence carries information.

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 6-parameter, zero-required, mutating tool with nested objects and no output schema or full annotation coverage, the description covers the key constraints but omits return behavior, prerequisites, and details on several parameters, leaving gaps an agent must infer.

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 only 33%, so the bar to compensate is higher; the description names the relevant parameters (suggestion, protocol, name, config) and explains the auto flag constraint, but says nothing about confirm semantics or the shape of suggestion/config objects.

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+resource: 'Hot-add a capability through the shared Policy Gateway', and ties itself to the sibling mcp_add by noting it takes the 'same path'. It's clear what the tool does, though it doesn't distinguish itself from mcp_add's role beyond the shared gateway.

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?

Gives usage hints ('Pass a suggestion or protocol/name/config') and a constraint for auto mode, but never says when to choose this tool over the many siblings like mcp_add, capability_configure, or capability_unregister. Usage is implied rather than explicitly scoped.

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