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

Beyond the readOnlyHint annotation, the description discloses the default exclusion of archived fields (and how to change it) and the fallback behavior when workspaceId is omitted (credential's workspace). It also encodes the value type mapping (checkbox=boolean, date=epoch ms, member=member ID), which is behavior an agent needs and annotations do not cover.

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 opening sentence is front-loaded with what the tool does and returns, and every subsequent sentence adds actionable information. However, the paragraph is dense with semicolon-chained clauses, which makes it slightly harder to scan than a punctuated list would be.

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 only two parameters, no output schema, and no annotation coverage beyond read-only, the description supplies the return shape, value types, default filtering behavior, and workspace resolution. Nothing an agent needs to invoke it correctly 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 0%, so the description carries the full burden, and it mostly does: workspaceId's optionality, default source, and discovery path are explained, and includeArchived's effect is stated. It could be marginally sharper on includeArchived's type (boolean), but the semantic intent of both parameters is clear.

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 ('Lista los campos personalizados del workspace') and even enumerates the returned attributes (id, nombre, type, orden). No sibling tool lists custom fields, and the mention of save_issue/get_issue ties it to the correct workflow, so an agent can identify it 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?

Explicitly names the downstream tools that consume these IDs ('save_issue acepta customFields: { <fieldId>: valor } y get_issue los devuelve') and explains that this call is the prerequisite for reading or writing custom field values. It also points to list_workspaces for obtaining the optional workspaceId, so the selection context is complete.

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