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

With no annotations provided, the description carries the full burden. It thoroughly discloses behavior: server-side sorting/filtering, sort column and direction options, case-insensitive regex search, date parsing rules (including end-inclusive behavior), date field binding, pagination specifics (0-indexed page, page_size range), and the return shape. It also notes 'Free, owner-scoped,' which is useful context.

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 description is front-loaded with its primary purpose and contains dense, relevant information. However, it is a single lengthy paragraph that could benefit from bullet points or section breaks for readability. Every sentence earns its place, but the structure is slightly overwhelming.

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?

Given there are no annotations, low schema coverage (10%), and an output schema that is not shown, the description provides a complete picture for a list operation. It covers all parameters, return shape, filtering semantics, pagination, and scope, making it quite complete for the task.

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 only 10% (only npub has an inline description). The description compensates fully by explaining every meaningful parameter: sort_col, sort_dir, search, date_from/date_to, date_field, page, page_size, and even mentions dpop_token indirectly as part of the auth context. It provides valid values, defaults, and semantic details like case-insensitivity and date formats.

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?

The description clearly states the tool's function: 'List your saved post snippets, server-side sorted, filtered, and offset-paginated.' It uses a specific verb and resource, and the context of listing snippets clearly distinguishes it from sibling tools like excalibur_get_snippet, excalibur_save_snippet, and excalibur_delete_snippet.

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 description provides clear context on when to use the tool—for listing, searching, and paginating through saved post snippets—and adds scope details ('owner-scoped'). However, it does not explicitly name alternative tools or say when not to use it, so it lacks explicit exclusion guidance.

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