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

With no annotations, the description carries the full burden and largely succeeds: it discloses privacy ('never public'), side effects ('put on you and shown on your page as written by you'), versioning ('same name again releases a new version'), and a hard validation rule with a workaround ('a skill with credentials is refused', use {{secret}}). It omits auth requirements, rate limits, and return behavior, but the mutation semantics are unusually well disclosed.

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?

A single dense paragraph that front-loads the action and format before moving to privacy, versioning, and the credential rule. Every clause earns its place, though the packing of five distinct facts into one sentence reduces scannability.

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, no-output-schema, no-annotation tool, the description covers the essentials an agent needs to call it safely: format, side effects, privacy, versioning, and the credential prohibition. The main gap is the absence of any explicit pointer to sibling skill tools.

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 the baseline is 3, but the description adds meaning: it expands the body contract ('a title, when to use it, how, pitfalls') beyond the schema's bare 'The skill in Markdown', and states the versioning consequence of reusing a name, reinforcing the schema's 'the same name updates 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+resource ('Save a skill you wrote for yourself') and clarifies scope ('your owner's private skill, never public'). It does not name the nearest siblings (submit_skill, install_skill), so the agent must infer the private-vs-public distinction from context rather than an explicit contrast.

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 a concrete when-to-use scenario ('e.g. how to work with your owner's custom API, learned from its docs') and the intended audience ('a skill you wrote for yourself'). It offers no explicit exclusions or named alternatives, so the agent must infer that public sharing is a different tool.

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