connector_slack_fetchRetrieve a single Slack resource by ID to pull messages, files, or records into local workflows, automation, or analysis.
Fetch a single resource from Slack by its ID.
| Name | Required | Description | Default |
|---|---|---|---|
| resource_id | Yes | Native resource ID to fetch |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description and name frame this as a read-only lookup ('Fetch a single resource'), while the annotations declare readOnlyHint=false and destructiveHint=true. That is a direct inconsistency: an agent told this is a fetch would not expect a destructive write, and an agent trusting the annotations would avoid a seemingly safe read. No side-effect, permission, or rate-limit context is offered to reconcile the two.
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?
One short, front-loaded sentence with no filler — the verb and the lookup key come first. It is efficient rather than padded, though it is thin rather than tight given the unresolved 'resource' ambiguity.
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 one-parameter tool with no output schema and 100% schema coverage, the description is minimal but survivable. It nonetheless leaves unresolved what 'resource' means, what ID form is expected, and how the destructive annotation squares with a fetch operation.
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% and the single parameter is documented as 'Native resource ID to fetch', so the schema carries the semantics. The prose adds nothing beyond that (no ID format, no examples, no statement of which Slack object types are addressable), 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?
The verb ('fetch') and the lookup key ('by its ID') are stated, and this does distinguish a single-object retrieval from the sibling connector_slack_search and connector_slack_act. However, 'a single resource' is generic — Slack resources include messages, channels, users and files — so the agent cannot tell what kind of object or ID this accepts.
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 phrase 'by its ID' weakly implies use when an ID is already known, but there is no explicit when-to-use, no when-not-to-use, and no sibling alternative named (e.g. use connector_slack_search when you only have a query rather than an ID).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.