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

Annotations already establish read-only, idempotent, non-destructive, non-open-world behavior, so the bar is lower. The description adds real value beyond them: it discloses that two URL formats are accepted (#-fragment and /g/ share) and points to the authoritative row-syntax resource, which the agent needs to interpret the result.

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 front-loaded sentence gives purpose, output shape, the sibling to chain with, and both accepted URL forms; a short second sentence supplies the syntax reference. No filler or redundancy.

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 an output schema present, return values need not be detailed, yet the description still characterizes the result as a list of equation rows and links the syntax documentation required to read them. Minor gaps remain around malformed-URL/error behavior, but nothing essential for correct invocation is missing.

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% and there is only one parameter, so baseline is 3. The description goes further by enumerating the two accepted URL forms, adding meaning the terse schema text ('An equation.io graph URL') does not convey.

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 (decode) and resource (equation.io link) and names the exact output (its list of equation rows). It also names the sibling encode_graph_url as the inverse operation and distinguishes the two accepted URL forms, so an agent can tell it apart from encode_graph_url and show_graph without opening a 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?

Gives a clear workflow context: decode so you can edit the rows and rebuild a link with encode_graph_url, which implicitly routes the agent to the sibling for the reverse direction. It stops short of explicit when-not-to-use guidance and never mentions show_graph, so the sibling set is only partially addressed.

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