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

Goes well beyond the annotations by disclosing that each call consumes the monthly link quota, gives concrete per-plan rate limits (Free 3/60s, Starter 6, Single 60), and states the call is sent once and never retried. Alias-collision failure behavior and the return payload are also described, which is rich, decision-relevant context for a non-idempotent write.

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?

The write marker, purpose and limits are front-loaded and the content is dense but useful. The trailing 'GET https://cutt.ly/api/api.php?short=...' fragment is an incomplete, low-value URL snippet that slightly muddies an otherwise tight description.

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?

With no output schema, the description correctly covers return values (short link, full link, page title), quota and rate-limit behavior. The only shortfall is the dangling endpoint fragment and no guidance on how this tool relates to cuttly_update_link for an existing link.

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 the schema already documents url, alias, public_stats and use_branded_domain. The description only reinforces the alias concept ('the part after the slash') and adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 and resource ('create a Cuttly short link for a long URL') plus the optional custom alias. The verb 'create/shorten' cleanly separates it from the sibling mutation tool cuttly_update_link and the read tools (stats), so an agent can route without opening the schema.

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?

The 'WRITE:' prefix and the quota/rate-limit notes imply when the tool is applicable, but there is no explicit when-not or named alternative (e.g. 'use cuttly_update_link to change an existing link instead of creating a new one'). Usage context is implied rather than stated.

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